The primary goal of the project is to develop mass spectrometry (MS) based assays for high throughput and quantitative biomarker validation with sensitivity and specificity comparable to or better than antibody based immunoassays. The analytical platform will be primarily based on triple quadrupole mass spectrometry with its sensitivity, dynamic range, measurement specificity and sample throughput significantly enhanced by integrating the latest high speed liquid chromatography (LC), high efficiency electrospray ionization (ESI) source and unique MS interface technologies developed at Pacific Northwest National Laboratory (PNNL) and extending the instrument capability from performing traditional multiple reaction monitoring (MRM) measurements into MRM2 MS analysis. The expected limit of quantitation and dynamic range for the new instrument based assays will be expected to reach low pg/mL level and span eight orders of magnitude in sample concentration allowing quantitative measurements of low abundance protein biomarkers in complex biofluids, such as human blood plasma. The new instrument based assays will be applicable to a broad spectrum of clinical cancer biomarker validation applications and capable of validating hundreds to thousands biomarkers in a single experiment. Their performance will be rigorously optimized and tested using clinical samples.